Reinforced polymer blends

ABSTRACT

Improved mechanical properties, particularly tensile strength, are demonstrated by glass fiber-reinforced blends of a polymeric blend comprising a major proportion of a polyamide polymer with a lesser amount of a linear alternating polymer of carbon monoxide and at least one ethylenically unsaturated hydrocarbon and, optionally, an acidic polymer containing moieties of α-olefin and α,β-ethylenically unsaturated carboxylic acid.

FIELD OF THE INVENTION

This invention relates to a polymer blend comprising predominately apolyamide polymer having recurring amide linkages within the polymerchain, which blend is reinforced by the presence therein of glassfibers. More particularly, the invention relates to a reinforced blendof the polyamide polymer with a lesser amount of a linear alternatingpolymer of at least one ethylenically unsaturated hydrocarbon and,optionally, a lesser proportion of an acidic polymer containing moietiesof an α-olefin and an α,β-ethylenically unsaturated carboxylic acid.

BACKGROUND OF THE INVENTION

The class of polyamide polymers which is the major polymeric componentof the blends of the invention has been known for many years. Thesepolymers, also known as Nylons, have gained extensive commercialrecognition in the production of numerous types of objects produced bymany of the methods conventional for the processing of suchthermoplastic polymers. Although the polyamides are useful in theformation of three-dimensional objects such as gears and motor housings,the most frequent use is probably in the production of fibers andfilaments and the yarns and fabrics produced therefrom. There are,however, certain limitations imposed by the properties of the polyamidepolymers which limit their usage in some applications. It would be ofadvantage to retain the more desirable properties of the polyamidepolymers and yet improve other properties, particularly when thepolyamide polymers are to be reinforced as by the presence ofreinforcing materials such as glass fibers. These advantages are oftenobtained through the provision of polymer blends.

Blends of polyamide polymers are known wherein the properties of thepolyamide have been modified. For example, Epstein, U.S. Pat. No.4,174,358, describes blends of a number of polymers in a polyamidematrix which are said to show improved ductility and toughness. Blendswherein the polyamide polymer is a major or component with lesseramounts of the linear alternating polymer of carbon monoxide and atleast one ethylenically unsaturated hydrocarbon and an acidic polymerare disclosed by copending U.S. patent application Ser. No. 429,915,filed 10/31, 1989.

Blends wherein the polyamide polymer is a minor component with a majorproportion of the linear alternating polymer are disclosed in U.S. Pat.No. 4,839,437. Such blends additionally containing an acidic polymerhaving moieties of α-olefin and α,β-ethylenically unsaturated carboxylicacid are disclosed in copending U.S. patent application Ser. No.429,913, filed 10/31, 1989. The presence of these minor componentsserves to improve certain of the properties of the linear alternatingpolymer. It has now been found that reinforced polymeric blends whereinthe polyamide polymer is the major component demonstrate improvement incertain properties upon blending with the linear alternating polymerand, optionally, with the acidic polymers.

SUMMARY OF THE INVENTION

The present invention provides blends of polyamide polymers with lesserproportions of other polymeric material, which blends are reinforced bythe presence therein of glass fibers. More particularly, the inventionprovides reinforced blends comprising major amounts of polyamide polymerwith lesser amounts of a linear alternating polymer of carbon monoxideand at least one ethylenically unsaturated hydrocarbon and, optionally,an acidic polymer containing moieties of an α-olefin, and anα,β-ethylenically unsaturated carboxylic acid, and an optional thirdmonomer, which acidic polymer optionally has a portion of the carboxylicacid groups neutralized with non-alkali metal. The blends of theinvention exhibit improved fiber-matrix adhesion and improved tensilestrength.

DESCRIPTION OF THE INVENTION

The major polymeric component of the blends of the invention is apolyamide polymer. By the term "polyamide" as used herein is meant alinear condensation product containing recurring amide linkages asintegral parts of the polymeric chain. These polyamide polymers are wellknown in the art and a number have been marketed commercially under thetrademark Nylon. The polyamide polymers which are useful in the blendsof the invention are crystalline or amorphous polymers of linear orbranched structure and have a molecular weight of at least 5000. Thepreferred polyamide polymers are linear in structure, wherein eachrecurring unit has up to 16 carbon atoms inclusive, and the polyamidepolymers have melting points in excess of about 200° C.

In one embodiment of the polyamide blend component the polyamide ishomopolymeric in character illustratively being a homopolymer of anaminocarboxylic acid of up to 16 carbon atoms inclusive. In preferredhomopolymeric polyamide polymers the polymeric unit can be thought of asderived from a straight-chain omega-aminocarboxylic acid of up to 16carbon atoms inclusive. It should be appreciated that the representationof the polyamide polymer of this embodiment as the homopolymer ofaminocarboxylic acid is for convenience and in practice the monomericunit is provided as an aminocarboxylic acid, a lactam or in anequivalent form. Typically, the homopolymeric monomeric unit is providedas a lactam, e.g., butyrolactam,. caprolactam or lauryllactam. Thesehomopolymeric polyamides are often referred to in terms of the number ofcarbon atoms in the monomeric unit. For example, the polyamide obtainedfrom polymerization of butyrolactam is termed Nylon 4 and thehomopolyamide obtained by polymerization of caprolactam is termed Nylon6. Of these homopolymeric materials, the polyamide preferred for use asa component of the blends of the invention is polycaprolactam or Nylon6.

In an alternate embodiment of the polyamide blend component thepolyamide is copolymeric in character and is illustratively representedas a condensation product of a primary diamine and a dicarboxylic acid.The primary diamine is preferably a terminal primary or alpha,omegaprimary diamine of up to 16 carbon atoms inclusive and having at leasttwo carbon atoms located between the primary amino groups located onterminal carbon atoms of the diamine structure. The diamines suitablycontain aromatic moieties linking the two primary amino groups asillustrated by p-phenylenediamine, 4,4'-diaminobiphenyl,di(4-aminophenyl)methane and di(4-aminophenyl) ether, or the diaminescontain cycloaliphatic linking groups as in the case ofdi(4-aminocyclohexyl)methane or 1,4-diaminocyclooctane. The preferreddiamines, however, are the acyclic terminal primary diamines of theformula

    H.sub.2 N--CH).sub.2 NH.sub.2                              (I)

wherein n is an integer from 2 to 16 inclusive. Suchpolymethylenediamines include trimethylenediamine,tetramethylenediamine, hexamethylenediamine, decamethylenediamine,dodecamethylenediamine and hexamethylenediamine. Of these diamines, theuse of hexamethylenediamine as precursor of the copolymeric polyamideblend component is preferred.

The dicarboxylic acid precursor of the copolymeric polyamide blendcomponent has up to 16 carbon atoms inclusive, preferably up to 12carbon atoms inclusive, and is illustrated by aromatic dicarboxylicacids such as isophthalic acid, terephthalic acid,4,4'-biphenyldicarboxylic acid and 2,6-naphthalenedicarboxylic acid, orby cycloaliphatic dicarboxylic acids such as 1,4-cyclohexanedicarboxylicacid, 1,5-cyclooctanedicarboxylic acid and 2,3-norbornanedicarboxylicacid. The preferred dicarboxylic acids, however, are acyclic aliphaticdicarboxylic acids, particularly those straight-chain dicarboxylic acidsof the formula

    HO.sub.2 C--CH).sub.m CO.sub.2 H                           (II)

wherein m is an integer from 0 to 14 inclusive, preferably from 0 to 10inclusive. Illustrative of such dicarboxylic acids are oxalic acid,pimelic acid, sebacic acid, suberic acid, adipic acid and azelaic acid.Of the acyclic aliphatic dicarboxylic acids, adipic acid is particularlypreferred.

It should be appreciated that the copolymeric polyamides are representedas the condensation product of primary diamines and dicarboxylic acidmonomer or even the primary diamine may suitably be provided in anequivalent form. For example, the dicarboxylic acid precursor of thecopolymeric polyamide is often provided as the dialkyl ester of thedicarboxylic acid. The copolymeric polyamides are also often named interms of the number of carbon atoms in the monomeric units, i.e., thenumber of carbon atoms in the diamine and the dicarboxylic acidmonomers. For example, the copolymeric polyamide illustratively producedfrom hexamethylenediamine and adipic acid is termed Nylon 6,6. Thecopolymeric polyamide illustratively produced from tetramethylenediamineand dodecanedicarboxylic acid is termed Nylon 4,12.

The polyamide blend components, whether homopolymeric or copolymeric,are well known materials and many polyamide polymers are commerciallyavailable from DuPont and others. The production of the polyamidepolymers is well known and conventional.

The blends of the invention comprise the polyamide component in majorproportion and lesser proportions of linear alternating polymer ofcarbon monoxide and at least one ethylenically unsaturated hydrocarbonand, optionally, an acidic polymer containing moieties of an α-olefinand an α,β-ethylenically unsaturated carboxylic acid, which blends arereinforced by the presence therein of glass fibers. The linearalternating polymers, now becoming known as polyketones or polyketonepolymers, have a repeating unit of the general formula ##STR1## whereinA is the moiety of ethylenically unsaturated hydrocarbon polymerizedthrough the ethylenic unsaturation. A variety of ethylenicallyunsaturated hyrocarbons of up to 20 carbon atoms inclusive, preferablyof up to 10 carbon atoms inclusive, are useful in the production of thelinear alternating polymer. Illustrative of such hydrocarbons areethylene, butylene, isobutylene, styrene, 1-octene and 1-dodecene. Thepreferred linear alternating polymers are copolymers of carbon monoxideand ethylene and terpolymers of carbon monoxide, ethylene and a secondethylenically unsaturated hydrocarbon of at least 3 carbon atoms,particularly an α -olefin such as propylene.

The preferred polyketone polymers for use as a component of the blendsof the invention are represented by the repeating formula

    --CO--CH.sub.2 --CH.sub.2)].sub.x [CO--G)].sub.y           (III)

wherein G is a moiety of the second ethylenically unsaturatedhydrocarbon of at least 3 carbon atoms, particularly propylene,polymerized through the ethylenic unsaturation thereof. The --CO--CH₂CH₂ -- units and the --CO--G-- units are found randomly throughout thepolymeric chain and the ratio of y:x is no more than 0.5. In theembodiment where linear alternating copolymers are employed as the blendcomponent there will be no second hydrocarbon present and the copolymersare represented by the above formula III wherein y is zero. Whenterpolymers are employed in the blends of the invention, the terpolymersare of the above formula wherein y is greater than zero and the ratio o-y:x is from about 0.01 to about 0.1.

The preferred polyketone polymers will typically have a number averagemolecular weight, as determined by gel permeation chromatography of fromabout 1000 to about 200,000, but more often from about 20,000 to about90,000. The polymers will have a melting point of from about 175° C. toabout 300° C. and a limiting viscosity number (LVN), measured inm-cresol at 60° C. in a standard capillary viscosiity measuring device,of from about 0.8 dl/g to about 4 dl/g. The linear alternating polymersare produced by contacting the carbon monoxide and ethylenicallyunsaturated hydrocarbon reactants in the presence of a catalystcomposition formed from a compound of palladium cobalt or nickel, theanion of a non-hydrohalogenic acid having a pKa below about 6,preferably below 2, and a bidentate ligand of phosphorus, arsenic orantimony. The scope of the polymerization process is extensive but,without wishing to be limited, a preferred catalyst composition isformed from a palladium alkanoate, particularly palladium acetate, theanion of trifluoroacetic acid or p-toluenesulfonic acid, and a bidentatcligand of phosphorus selected from 1,3-bis(diphenylphosphino)propane or1,3-bis[di(2-methoxyphenyl)phosphino]propane. The general processes forthe production of the linear alternating polymer is illustrated by anumber of published European Patent Applications including 121,965,181,014, 213,671 and 257,663.

The polyketone polymer is employed in the blends of the invention as aminor component relative to the polyamide polymer. Amounts of polyketonepolymer as low as 1% by weight, based on total polymeric blend, will beof benefit. On the other hand, the production of blends having more thanabout 20% by weight of polyketone and a major or proportion of polyamideis difficult so that about 20% by weight of polyketone in a majorproportion of polyamide polymer represents a practical upper limit onthe proportion of polyketone polymer blend component. Preferredquantities of polyketone are from about 5% by weight to about 15% byweight of polyketone based on total polymer blend.

The optional third polymeric component of the blends of the invention isan acidic polymer of an α-olefin and α,β-ethylenically unsaturatedcarboxylic acid, optionally containing a third monomer and optionallyhaving a portion of the carboxylic acid groups neutralized withnon-alkali metal. The α-olefin precursor of the optional third polymericblend component is an α-olefin of up to 10 carbon atoms inclusive asillustrated by ethylene, propylene, 1-butene, isobutylene, 1-octene and1-decene. The preferred α-olefins are straight-chain α-olefins of up to4 carbon atoms inclusive and particularly preferred is ethylene. Theα-olefin component of the optional third polymeric blend component ispresent in a quantity of at least about 65% by mole of any thirdpolymeric blend component and is preferably present in at least 80% bymole on the same basis.

The unsaturated carboxylic acid monomer of the optional third polymericblend component is an α,β-ethylenically unsaturated carboxylic acid ofup to 10 carbon atoms inclusive and is illustrated by acrylic acid,2-hexenoic acid, 2-octenoic acid and 2-decenoic acid. The preferredα,β-ethylenically unsaturated carboxylic acids have up to 4 carbon atomsinclusive. These acids are acrylic acid, methacrylic acid and crotonicacid, of which acrylic acid and methacrylic acid are particularlypreferred. The unsaturated acid monomer of the optional third polymericblend component is present in an amount of from about 1% by mole toabout 5% by mole, based on total acidic polymer, but amounts ofunsaturated carboxylic acid from about 5% by mole to about 20% by moleon the same basis are preferred.

The optional acidic polymer blend component is suitably a copolymer ofthe α-olefin and the α,β-ethylenically unsaturated carboxylic acid andin general such copolymers are preferred. On occasion, however, it isuseful to incorporate within the acidic polymer as an optional thirdmonomer a non-acidic, low molecular weight polymerizable monomer of upto 8 carbon atoms inclusive. Such optional third monomer may be a secondα-olefin such as propylene or styrene when the major α-olefin isethylene, an unsaturated ester such as vinyl acetate, methyl acrylate orethyl methacrylate, an unsaturated halohydrocarbon such as vinylfluoride or vinyl chloride, or an unsaturated nitrile such asacrylonitrile. As previously stated, the presence of a third monomer isoptional and is not required. Amounts of the non-acidic low molecularweight polymerizable monomer up to about 5% by mole, based on totalacidic polymer are satisfactory with amounts up to about 3% by mole onthe same basis being preferred.

Independent of whether the acidic polymer employed as an optional thirdpolymeric blend component is a copolymer or a terpolymer, in analternate embodiment of this optional blend component a portion of theacidic carboxylic acid groups are neutralized with non-alkali metal.When partially neutralized, the blend component is polymeric in formwhile exhibiting ionic character and these materials are conventionallyreferred to as metal ionomers. In the partially neutralized embodiment,the α-olefin/unsaturated acid polymer with or without the presence ofthe optional third monomer, is reacted with a source of ionizablenon-alkali metal compound, preferably ionizable zinc, aluminum ormagnesium compound, sufficient to neutralize from about 10% to about 90%of the carboxylic acid groups present in the polymer. Suchneutralization, particularly with zinc, the preferred metal, results ina uniform distribution of metal through the polymer. Neutralization offrom about 20% to about 80% of the carboxylic acid groups present ispreferred in this embodiment and neutralization of from about 25% toabout 75% of the carboxylic acid groups is particularly preferred. Theionizable metal compound utilized in the neutralization is a source ofuncomplexed non-alkali metal ions including zinc ions, aluminum ions ormagnesium ions which are provided in the form of compounds of the typereferred to as metal salts, e.g., zinc acetate, zinc formate or zincpropionate, or is a source of complexed metal ions wherein the metal isbonded to two types of groups, at least one of which is readily ionizedand at least one other group is not. Illustrative of such complexedmetal ions are mixed zinc salts with one weak acid such as oleic acid orstearic acid and one more readily ionizable acid such as acetic acid orformic acid. In general, neutralization with a complexed metal ion ispreferred in this embodiment.

The acidic polymers employed as optional third polymeric blendcomponents, optionally partially neutralized, are conventional and wellknown and many are commercial. Copolymers of ethylene and acrylic acidare marketed by Dow under the trademark PRIMACORE® and copolymers ofethylene and methacrylic acid are marketed by DuPont under the trademarkNUCREL®. Partially neutralized polymers are marketed by DuPont under thetrademark SURLYN®. As stated, the presence of acidic polymer is optionaland none is required. Amount of the optional third polymeric blendcomponent up to about 10% by weight, based on total blend, aresatisfactory. Amounts up to about 5% by weight on the same basis arepreferred.

The polymeric blends of the invention are reinforced by the presencetherein of glass fibers. The term "glass" is employed in theconventional meaning to indicate that class of metal silicates which arecommonly referred to as glasses. Although the addition of rare earthmetal oxides or transition metal oxides to other metal silicates will onoccasion produce a glass of rather exotic properties, the glass fromwhich the glass fiber reinforcement of the blends of the invention isproduced is the more common alkali metal silicate glass, particularly asodium silicate glass. Fibers produced from such glass are conventionaland are commercially available from a number of U.S. and foreign glasscompanies. The fibers are useful as reinforcements for polymericproducts and are commercially used as such. However, the physicaldimensions of the glass fibers are of some importance to successfulutilization in a particular application as are the presence or absenceof a sizing material or a coupling agent for the glass and the nature ofsuch sizing or coupling agent.

In the reinforced blends of the invention, the glass fibers whichcontribute the most desirable properties to the composition are choppedglass fibers of circular cross-section. The fibers range in diameterfrom about 2×10⁻⁴ inch to about 8×10⁻⁴ inch to about 7×10⁻⁴ inch. Fibersof greater or lesser diameter are satisfactory but fibers of too small adiameter do not provide the desired strength and fibers of too large adiameter contribute too much weight for the resulting strength and maynot be economical. Although in some applications the long continuousfibers of glass are satisfactory, in the compositions of the inventionit is preferred to use short fibers of glass. Lengths of glass fiberfrom about 0.1 inch to about 0.5 inch are suitable. While somewhatshorter or somewhat longer lengths are also useful, too long a glassfiber detracts from the processability while too short a fiber does notprovide the desired strength. It is recognized that the actual length ofthe glass fiber in the reinforced composition will depend to some extentupon the method of blending or mixing the components as the mixing orblending may mechanically reduce the length of the glass fibers.

The glass fibers to be used as reinforcement for most plastic materialswill customarily be provided by the manufacturer with a coating of asizing material or a coupling agent, which terms are often usedinterchangeably. The nature of the sizing or coupling agent willinfluence the interfacial strength of the fiber and the polyamidepolymer matrix, i.e., the degree to which the fiber and the polymer willadhere. Improvement in mechanical properties such as tensile strengthresult when a relatively high degree of adhesion occurs between thepolymer and the fiber. To contribute strength to a polymer blend, theinterfacial shear strength must he at least comparable in magnitude tothe shear strength of the polymer. Consequently, there must be goodadhesion between the polymer and the glass fiber. The interfacial shearstrength is influenced by the polarity of the polymer so that for somepolymers certain sizings or coupling agents work better than others. Foruse with the polymeric b-ends of the invention, a variety of sizings areavailable. Such sizings are generally characterized by the overallnature of the size rather than the specific chemical structures whichare often proprietary to the glass fiber manufacturer. Suitable sizinginclude water emulsions of starch and lubricating oil, aqueousdispersions of surface active materials and lubricants,silicon-containing materials such as vinyl silanes,alkyltrimethoxysilanes, amino silanes, trimethoxysilanes which may alsocontain urethane, acrylate or epoxy functionalities, and non-polarhydrocarbons. For use in the reinforced blends of the invention, glassfibers having polar sizings are preferred, for example, a sizing havinga trimethoxysilane end group attached to a hydrocarbon chain with aterminal methane functionality, although other hydrocarbon sizingshaving a trimethoxysilane end group are also suitable. Such fibers arecommercially available and are exemplified by OCF 492 Fiberglass and OCF457 Fiberglass which are commercially available from Owens-CorningFiberglass.

The amount of glass fiber to be incorporated into the compositions ofthe invention is a minor amount relative to the polymer present as themajor component of the total reinforced composition. Amounts of glassfiber from about 1% by weight to about 45% by weight, based on totalreinforced composition, are satisfactory with amounts from about 5% toabout 35% by weight on the same basis being preferred.

The method of producing the compositions of the invention is notcritical so long as an intimate mixture of the components is produced,i.e., a uniform mixture which will not delaminate on processing. In onemodification, the components are blended by passing a mixture of thepolymeric blend components in finely divided form and the glass fibersthrough an extruder operating at elevated temperature and high RPM toproduce the blend as an extrudate. In an alternate modification, thecomponents are blended in a mixing device operating at high shear andthermal energy. The reinforced compositions of the invention may containother materials such as antioxidants, stabilizers, mold release agents,fire retardant chemicals and other materials which are designed toimprove the processability of the polymeric blend components or modifythe properties of the reinforced composition. Such additives areincorporated prior to, together with or subsequent to the blending ofthe components and the mixing with the glass fibers. The resultingcompositions are processed by conventional methods such as injectionmolding, pressure forming, sheet extrusion and other procedures which donot serve to degrade the reinforced composition. The polymer/fiber glasscomposition are uniform blends which exhibit less mold shrinkage andhave improved mechanical properties, particularly tensile strength. Thecompositions have particular utility in the production of mechanicalparts, e.g., automobile body panels and fenders, especially those havinga large and continuous surface where toughness, strength and appearanceare important.

What is claimed is:
 1. A fiberglass-reinforced polymer blend comprising a major proportion of a polyamide polymer containing recurring amide linkages as integral parts of the polymer chain and a molecular weight of at least 5000, and a minor proportion of linear alternating polymer of carbon monoxide and at least one ethylenically unsaturated hydrocarbon and, optionally, an acidic polymer contaiing moieties of α-olefin, α,β-ethylenically unsaturated carboxylic acid and optionally a non-acidic, low molecular weight polymerizable third monomer of up to 8 carbon atoms, which acidic polymer optionally has a portion of the carboxylic acid groups neutralized with non-alkali metal.
 2. The reinforced blend of claim 1 wherein the linear alternating polymer is represented by the repeating formula

    --CO--CH.sub.2 --CH.sub.2)].sub.x [CO--G)].sub.y

wherein G is a moiety of an ethylenically unsaturated hydrocarbon of at least 3 carbon atoms and the ratio of y:x is no more than about 0.5.
 3. The reinforced blend of claim 2 wherein the acidic polymer is a copolymer of ethylene and acrylic acid or methacrylic acid, present in an amount of up to about 10% by weight, based on total blend.
 4. The reinforced blend of claim 3 wherein glass fiber is present in an amount of from about 1% by weight to about 45% by weight, based on total reinforced composition.
 5. The reinforced blend of claim 4 wherein the polyamide polymer is homopolymeric having a recurring unit of up to 16 carbon atoms inclusive.
 6. The reinforced blend of claim 5 wherein y is zero.
 7. The reinforced blend of claim 5 wherein the ratio of y:x is from about 0.01 % to about 0.1.
 8. The reinforced blend of claim 7 wherein the linear alternating polymer is present in an amount from about 1% by weight to about 20% by weight, based on total polymeric blend.
 9. The reinforced blend of claim 8 wherein the polyamide polymer is polycaprolactam.
 10. The reinforced blend of claim 9 wherein G is a moiety of propylene.
 11. The reinforced blend of claim 10 wherein the acidic polymer is a non-neutralized copolymer of ethylene and acrylic acid.
 12. The reinforced blend of claim 10 wherein th acidic polymer is a non-neutralized copolymer of ethylene and methacrylic acid.
 13. The reinforced blend of claim 4 wherein the polyamide polymer is copolymeric of recurring units of primary diamine and dicarboxylic acid of up to 16 carbon atoms inclusive.
 14. The reinforced blend of claim 13 wherein the primary diamine is of the formula

    H.sub.2 N--CH.sub.2).sub.n NH.sub.2

wherein n is an integer from 2 to 16 inclusive.
 15. The reinforced blend of claim 14 wherein the dicarboxylic acid is of the formula

    HO.sub.2 C--CH.sub.2).sub.m CO.sub.2 H

wherein m is an integer from 0 to
 14. 16. The reinforced blend of claim 15 wherein y is zero.
 17. The reinforced blend of claim 15 wherein the ratio of y:x is from about 0.01 to about 0.1.
 18. The reinforced blend of claim 17 wherein the linear alternating polymer is present in an amount from about 1% by weight to about 20% by weight, based on total polymeric blend.
 19. The reinforced blend of claim 18 wherein the primary diamine is hexamethylenediamine.
 20. The reinforced blend of claim 19 wherein the dicarboxylic acid is adipic acid.
 21. The reinforced blend of claim 20 wherein G is a moiety of propylene.
 22. The reinforced blend of claim 21 wherein the acidic polymer is a non-neutralized copolymer of ethylene and acrylic acid.
 23. The reinforced blend of claim 21 wherein the acid polymer is a copolymer of ethylene and methacrylic acid. 